Re: Decay space debris ID

Alan Pickup (
Sun, 24 May 1998 00:20:26 +0100

YK Chia <> asks

>    Can anyone out there tell me how to report re-entry phenomena and
>how to get help to identifywhich object is involved.

Keep in mind that the vast majority of bright fireballs are meteors and
not re-entries. Some organisations collect observations of such events;
for example, here in the UK the British Astronomical Association
requests that observers submit their reports to Howard Miles, Lane Park,
Pityme, St Minver, Wadebridge, Cornwall PL27 6PN. There are probably
other centres worldwide - can other SeeSaters provide addresses?

If you post your observation(s) here on SeeSat, I (and others, I assume)
would be happy to help in identifying any potential re-entry. The sort
of information we'd like is:

    o  Your location (latitude and longitude and/or name of town etc);
    o  Date and time of observation (specify the time zone and provide
         a UTC time if you can make the conversion);
    o  As much info about location and track in the sky as possible!
         Altitude (degrees) and direction when first and last seen. How
         long in seconds was the event visible? If seen at night, are
         you able to describe the track with respect to the stars and
         constellations? How did the angular speed compare with meteors
         and satellites you have seen?
    o  Appearance, eg single luminous object, or several in train?
         Colour? Brightness?
    o  Were any sounds heard? When, relative to the time of the visible

>    What about TLE for decayed satellite on the day of predicted

NASA's Orbital Information Group (OIG) publish the latest elsets for all
unclassified (non-secret) objects. For objects close to decay, I compile
these into my dklist.tle file which is updated several times daily and
is available via my WWW page below. However, you can query OIG yourself
for the final published elsets for recent decayers. Log in and register
with OIG at
One of the pages they offer is "Satellite Catalog Action Report". select
this and under "Data type" check "Header and TLE". This page will
include the final elsets for recently decayed elsets. Since these may be
hours before the actual re-entry, you may wish to use my SatEvo program
to project the elset forwards in time, closer to the re-entry. Be
warned, though, that a good idea of the actual decay time usually
requires an analysis based on several elsets over the final day or two.

 Alan Pickup | COSPAR site 2707:   55d53m48.7s N   3d11m51.2s W    156m asl
 Edinburgh   | Home:       +44 (0)131 477 9144
 Scotland    | SatEvo satellite page: